Re: [SQL] SQL-Query 2 get primary key
D'Arcy Cain <darcy@druid.net>
From: "D'Arcy" "J.M." Cain <darcy@druid.net>
To: grimme@atix.de (Marc Grimme)
Date: 1999-02-20T04:07:22Z
Lists: pgsql-hackers
Thus spake Marc Grimme
> if I create a table like this:
> CREATE TABLE test (
> id decimal(3) primary key,
> name varchar(32));
>
> how can I ask postgres which is the primary key from table test?
SELECT pg_class.relname, pg_attribute.attname
FROM pg_class, pg_attribute, pg_index
WHERE pg_class.oid = pg_attribute.attrelid AND
pg_class.oid = pg_index.indrelid AND
pg_index.indkey[0] = pg_attribute.attnum AND
pg_index.indisprimary = 't';
That lists all the primary keys in your database. Add a "WHERE pg_class
= 'test'" clause to get the specific table.
Note that this makes the assumption that only one field can be in the
primary key (no complex primary keys) but I don't think there will
ever be more than one the way we declare it now.
--
D'Arcy J.M. Cain <darcy@{druid|vex}.net> | Democracy is three wolves
http://www.druid.net/darcy/ | and a sheep voting on
+1 416 424 2871 (DoD#0082) (eNTP) | what's for dinner.